DESIGN AND OPERATIONS OF SUSTAINABLE SYSTEMS

OBJECTIVES:  To design and select materials for a reliable shaft/bearing assembly that can be used for the above mechanical structure and minimises friction, wear and maintenance. To construct a reliability block diagram (RBD) analysis for the electric car model and perform failure mode effects analysis (FMEA) for the same model.  To propose a monitoring system (sensory- actuation system) that can be used to monitor system operational condition and prevent system/ sub-systems failure. BRIEF: As an engineer in the ‘ROHM Semiconductor Automotive Solutions Ltd’ company you have been asked to design the bearing for the rear wheel and suspension system. In addition to the bearing design you are also requested to construct a reliability block diagram, perform FMEA analysis and propose a monitoring system for the above prototype. The design process should take into consideration the main dimensions of the mechanical structure and materials of the shaft and bearings. You will need to estimate the size and weight of the rear wheel and to make realistic assumptions about the driving speed and suspension system. Provide a detailed, professional report that contains the following items mentioned below: 1. Selection of dimensions of rear wheel and estimation of the torque, speed and power. Define the design parameters and state any required assumptions. Hint1: The dimensions are not given, you decide. The only condition is that it should fit in the existing design of the model vehicle. You can make it as small or big as you wish as long as it serves the intent purpose. Use the basic bending and torsion equation formulae for calculating the stresses and loads. 2. Selection of rolling element bearing diameter. You will need to justify your selection. Selection of bearing (diameter/width), calculation of forces and pressure on the bearing. Hint2: The weight of the rear wheel and suspension system is not given and need to be estimated or assumed by you. 3. Look through different online resources to find the failure data for various components of the electric car model. Construct a reliability block diagram (RBD) analysis for the rear wheel and suspension system of the Electric Car model. List out all the assumptions you have made in the construction of the RBD (e.g. failure criteria, failure/repair interval, maintenance strategy, etc.) Hint3: Websites mentioned below could be useful however you should also search for more specific data and put your findings in a table with references cited. [login to view URL] [login to view URL] 4. Perform the Failure Mode Effects Analysis (FMEA) on the electric car model. Discuss and compare the salient features of similarities and differences of the quantitative method like RBD over qualitative method like FMEA. Hint4: Review the FMEA method and perform the FMEA analysis on the electric car. 5. Propose a monitoring system (sensory - actuation system) that can be used to: - Monitor the operating condition of the car transmission - Predict the failure transmission elements. Describe in detail the main elements of the system. Use block diagrams to support your discussion. Hint5: You have to think about an actuator to prevent failure.